97% of the water on earth is in the oceans. Less than one percent of water on the earth's surface is suitable and readily available for direct consumption by human population and industries. Most of the surface fresh water is provided by rivers and lakes. Many places that do not have the geographic benefit of being close to such rivers and lakes suffer from a scarcity of fresh water. While transportation of fresh water from lakes and rivers through long pipelines and drawing underground fresh water have been popular solutions, such resources are becoming scarcer.
The leading technology for seawater desalination is reverse osmosis (RO), which can be effective in producing drinking water from ocean or brackish waters, but has several drawbacks in terms of environmental impact and energy consumption. Specifically, the reverse osmosis process releases large amounts of high salt concentration rejected water back into the ocean. Typically, for each gallon of water, 1-4 gallons of highly salted water is rejected. The impact on the environment is a significant concern with RO technology. Further, the reverse osmosis process is energy-intensive. Energy consumption in a reverse osmosis process ranges from 2.5 kWh/m3 in large size modern state-of-the-art RO plants to over 5.5 kWh/m3 in smaller size RO systems. Thus, there is a need for an environmentally friendly and low-energy desalination technology.